At present, nanoparticles such as oxide nanoparticles, nitride nanoparticles and titanium carbide nanoparticles are used in the production of sintered bodies for use as electrical insulation materials for semiconductor substrates, printed circuit boards, various electrical insulation parts and the like, materials for high-hardness and high-precision machining tools such as cutting tools, dies and bearings, functional materials for grain boundary capacitors, humidity sensors and the like, and precision sinter molding materials, and in the production of thermal sprayed parts such as engine valves made of materials that are required to be wear-resistant at a high temperature, as well as in the fields of electrode or electrolyte materials and various catalysts for fuel cells.
Of the above-described nanoparticles, titanium carbide nanoparticles are produced by, for example, the production methods disclosed in Patent Literatures 1 and 2.
The purpose of Patent Literature 1 is that homogeneous and fine titanium carbide powder (titanium carbide nanoparticles) can be easily obtained. Patent Literature 1 discloses a method of producing titanium carbide which involves baking oxidized titanium and carbon in a non-oxidizing atmosphere at a temperature of 1,300° C. to 1,800° C. In Patent Literature 1, oxidized titanium with an average particle size of 0.05 μm or less is added as an additive in an amount of 0.05 to 30 parts by weight with respect to 100 parts by weight of oxidized titanium with an average particle size of 0.1 to 5 μm.
Patent Literature 2 aims at providing homogeneous, coarse titanium carbide powder that can provide a homogeneous sintered body or homogeneous, coarse titanium carbide powder for use in the field of titanium carbide and the like to be used in conductive polymers, as well as a production method thereof.
Patent Literature 2 discloses a method of producing titanium carbide powder which uses oxidized titanium and carbon as materials to perform reduction and carbonization in a hydrogen atmosphere at a temperature of 1,500 to 1,750° C.
Patent Literature 2 discloses using the oxidized titanium as a material that has a primary particle size of up to 1 μm and a BET value of 2 m2/g or more, and using, as a carbon source, carbon black in which primary particles have a particle size of up to 0.5 μm and are not continuously bound to one another.
In addition, it is described in the literature that the particle size of the titanium carbide powder is controlled by adding either or both of Co and Ni in an amount of 0.1 to 0.3 wt % based on the weight of titanium carbide powder in the material mixing step prior to thermal treatment and heating the mixture at a temperature of 1,500 to 1,750° C.